Development of micellar electrokinetic chromatography method for the determination of three defined impurities in indomethacin

A micellar electrokinetic chromatography method for the determination of indomethacin impurities (4‐chlorobenzoic acid, 5‐methoxy‐2‐methyl‐3‐indoleacetic acid, and 3,4‐dichloroindomethacin) has been developed. A 64.5/56‐cm fused silica 50 μm id capillary with extended light path (150 μm id) detection window was used. Internal standard was 1‐naphthylacetic acid. The analytes were separated at 30 kV with DAD detection at 224 nm. A central...